ABSTRACT: Tectonostratigraphic Evolution of Neuquen Basin, Argentina

EISNER, PABLO N., ALBERT W. BALLY, and PETER R. VAIL, Rice University, Houston, TX

Neuquen basin is a mature basin with a long history of hydrocarbon production. It is the second most productive basin in a country that is self-sufficient in oil. The area is located in west-central Argentina, east of the Andes. It was a Mesozoic backarc basin that evolved into a foredeep basin when a fold and thrust belt was formed to the west during the Upper Cretaceous.

The sedimentary infill is Permian-Triassic to Tertiary. It is continental and marine in origin and was deposited in a generally shallow, slowly subsiding basin. The main factor that helps subdivide the stratigraphy of the basin is relative changes of sea level. Detailed sequence stratigraphic analysis of Upper Jurassic to Lower Cretaceous clastics, carbonates, and evaporites explain the mechanisms by which subtle stratigraphic traps may be created.

The Neuquen Dorsal, a positive east-west structure in the relatively undeformed basin, has been tentatively interpreted as an inversion. This hypothesis must be further analyzed using additional data. Deformation in the fold and thrust belt took place from the Campanian to the Pliocene and shows three distinct zones. From east to west a broad arch is followed by an intricate series of tight anticlines formed by both east- and west-verging thrusts that use four different decollement surfaces. To the west of these, an east-verging ramp anticlinal structure is identified, which involves deeper decollement surfaces.

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)